Walnut, IA 51577 Weather

Key messages

- A low- end severe threat develops after 5 PM from western Iowa to far southeast Nebraska. Better chances for rain fill in early Friday through Saturday.

- A strong storm system moves into the region early next week, bringing another round of showers Monday into Tuesday. Some heavy rain is possible.

Discussion

Issued at 130 PM CDT Wed Oct 28 2026

The morning started off with dense fog in northeast Nebraska and isolated weak thunderstorms near the Missouri borders of Nebraska and southwest Iowa. Low ceilings remain in place north of the Platte River this afternoon as a cold front inches farther into the forecast area. It is tied to a sfc low in far northeast South Dakota.

Southerly winds have pushed temps into the 70s ahead of the front, but dewpoints have trailed by 10-15 degrees which leaves expected sfc based instability on the lower side (1400 J/kg or less). Forcing for ascent will be better across Minnesota and closer to the low pressure center later this evening. Best chances across Nebraska and Iowa will be directly along the cold front where forcing is maximized and instability peaks due to moisture pooling ahead of the front. Shear is sufficient for large hail should any supercells develop, but the threat is conditional. In other words, likelihood of initiation is low (25%), but *should that happen*, the chance of severe weather is decent (20% threat of any such storm becoming severe). Put that math together and you're looking at a 5% chance of severe weather at any given point in western Iowa and south of I-80 in eastern Nebraska.

The front and storm chances will be out of the CWA by midnight.

Overnight lows will range from lower 60s near Missouri to lower-40s closer to South Dakota. RH values may fall shy of the century mark overnight, but with light winds under the sfc high, wouldn't be surprised to see patchy fog development: especially anywhere impacted by rain earlier in the evening. If temps slipped a little bit cooler than forecast, fog may need to be added to the grids.

Thursday

Temps will slip a few degrees cooler on Thursday with the day's warmest numbers peaking in the lower-70s. Easterly winds will flow at 5-15 mph under sunny skies.

Thursday night brings another good chance of precip, especially after midnight as the southwest flow pushes a shortwave through the area. Ascent will be aided by the LLJ lifting over the front stalled across the NE/KS state line. PoPs of 60-75% are in place for all but the northern two tiers of Nebraskan counties of the forecast area.

Friday

Friday morning may see showers wrap up early before a drier spell mid-day. Attendees of holiday parties and Friday football games will need to prepare wardrobes for more showers on Friday night. Again, strong southerly wind will drive Gulf moisture directly over the front draped along the southern edge of the forecast area. Unfortunately, ingredients for at least some lightning and thunder do look to be available. Severe weather doesn't look likely.

The weekend and beyond

Rain chances (60 -> 20%) fade over the course of the day on Saturday which itself has had an overall drying trend in successive model runs. High temps remain above seasonal norms, peaking in the 60s. Southerly winds should remain slow enough to not impact trick- or- treaters. Evening temps will fall close to 60F by 8pm.

Sunday is a near repeat of Saturday and few will complain.

The primary story of the extended forecast is the threat of a deep cutoff low traversing the central CONUS early in the week. Plenty of question marks remain in timing and location of the upper and sfc low. Some guidance suggests 2-3" of accumulation is possible when all said and done. As it stands, temps will remain well above freezing and will preclude the threat of snow. But considering the uncertainty, I would not be surprised to see this change before the date arrives - especially behind the departing system on Tuesday / Wednesday (deformation zone).

Aviation

Issued at 602 PM CDT Wed Oct 28 2026

VFR conditions are anticipated through the period. A cold front is currently located from near HNR to OMA to LNK. Showers with isolated thunderstorms have developed along and ahead of the front. Any potential aviation impacts will move east of OMA and LNK over the next hour as the front continues to move east. Showers and thunderstorms will continue across southeast Nebraska and western Iowa this evening before exiting the region around 06Z. Winds become northwesterly behind the front, becoming light from the north over the next few hours. Winds back around to the east during Thursday morning.

Watches, warnings and advisories

NE: None. IA: None.